December in Iowa City averages a daily high of 2.2°C with nights around -6.9°C. Expect roughly 8.1 wet days totalling 36.4mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Iowa City is August–October.
Based on IOWA CITY MUNICIPAL AIRPORT, IA US (2.7km), 1995–2024. 30 years of December data.